Neither would make a ripple in the overall stock price. As an example, today there have been 10M shares of GM traded and more will hit just before the bell as more programmed trading hits.

There would be times that I will do all in on one stock that I think will pop 2-5%. The GM stock, I felt would pop 5% and was watching it very close as it blew by 5 up to 20 in a heartbeat. I then put a sell order in IF if got back down to the 20% number as a safety net. I watched it longer and bailed on it at 29%. It kept going up BUT I was content with a 29% pop on a 5% expectation. It's like going to pick up a blind date and realizing you have twin cheerleaders. Sometimes it just works out.

So what trading facility do you favor for placing conditional orders, etc?

1) I'm not going to do anything before I've done several months / maybe a year's worth of trial runs, or until I'm VERY confident that I'm right a fat majority of the time.

2) I'm not going to do anything with money I cannot afford to lose. Something like this could be one and done inside a few hours. If that's the case, so be it.

3) I'm not quitting the day job until I know I can retire, or until enough time and experience have accumulated that I'd be more profitable quitting.

That will change once you're actually risking something. Trust me on this. In the land of make-believe there is no second guessing, no self doubt, no shaken confidence, no psychological repercussions from taking it on the chin once in a while. Risk introduces an element of fear that trials cannot consider.

"If spending money you don't have is the height of stupidity, borrowing money to give it away is the height of insanity." -- anon